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photo:lenses

camera lenses

choosing a lens

a lens as an investment - reliability and redundancy

  • many photographers will tell you that money spent on a good lens will be a better investment than money spent on the camera
  • this is historically generally true
  • money spent on “kit” zoom lenses is generally not a good investment as these lenses generally have average build quality, average optics and poor apertures which severely limits their utility in low light and for creating blurred backgrounds
  • users are generally advised to buy a wider aperture lens of better optical quality
  • digital cameras in particular now are almost “disposable” with even the high end expensive cameras having a real life of perhaps only 5-7 years, and will depreciate rapidly in value as they will be surpassed by cameras with more features, better sensors and better AF, IS, HD video and connectivity technologies
  • high quality, mechanical, manual focus lenses will generally last for decades if they are not dropped, scratched or allowed to develop fungus on the optics
  • modern AF lenses will fail over time as they have rapidly moving parts and electronic components - both have failure rates and when used frequently are likely to fail over their 1st 10 years
    • this failure rate is dependent upon build quality and lens complexity
    • the failure rate tends to be highest with AF zoom lenses with optical image stabiliser, in particular, the pro 70-200mm IS lens appear to be particularly likely to fail1)
  • additionally the lens features may make it redundant over time - particularly as an investment:
    • the AF motors in the lenses are continually improved, particularly for the new contrast detect AF cameras which rely on newer technology AF motors
    • the image stabiliser technology continues to improve making older lenses less effective
    • optics tend to be developed over time to provide improved sharpness to better match the higher pixel density in modern sensors - old lenses often do not allow these sensors to shine
  • those purchasing a system may well consider the benefits of buying a system where the image stabiliser is built into the camera such as Sony Alpha dSLR system or Micro Four Thirds system, as this not only means EVERY lens gains IS capability without requiring optical IS and its increased failure and redundancy rates, and you potentially gain the benefit of improved IS every time you upgrade the camera to a newer camera which you will have to do anyway with any system.
  • those who cannot tolerate extended outages from delays in repair, need to consider access to service and turnaround times - this is a major reason why many pros stick with Canon or Nikon as they are more accessible worldwide
  • finally, demand for particular lenses changes over time
    • the current trend is for smaller, sharper, wide aperture, more silent lenses with fast AF

what focal length?

  • this is not an easy question to answer as it entirely depends upon YOU like to photograph
  • the following are focal lengths in terms of a 35mm full frame camera system
  • most will be able to photograph most subjects they need with just 3 lenses:
    • compact, light 3x zoom lens covering 24-70mm region
    • compact wide aperture 35-40mm prime lens
    • wide aperture short telephoto lens
    • other lenses as per their individual needs
  • use Lens-GAS free software to rapidly chart the focal lengths of the photos in a folder to see which ones are most commonly used

the compact travel zoom lens

  • this is the lens you take when you have plenty of light (eg. outdoors, daytime), and you really have no idea what you might suddenly want to photograph, so a range of focal lengths becomes very handy
  • you will have to decide upon the compromises of zoom range, aperture, image quality, cost, weight and size
  • for many, a small, light 3x zoom lens covering 24mm-70mm or 28-85mm will fit the bill
  • some who are prepared to carry a heavier, longer lens, may opt for a 10x zoom covering 28-280mm
  • enthusiasts may opt for a f/2.8 aperture 3x zoom lens for improved low light capability - one of the smallest, and lightest is the Panasonic 12-35mm f/2.8 X HD weatherproof lens which covers 24-70mm and the Panasonic 35-100mm f/2.8 OIS X which covers 70-200mm, but these are not cheap.

compact, low light party/candid/street lens

  • this is generally a lens in the range of 35-40mm focal length with an aperture f/2.0 or wider
  • it is great for candid or street photography and is awesome for taking to social events because it is small, will focus in low light, potentially allow available light shots indoors if image stabiliser is available, and can be combined with a bounce flash for really nice group portraits

wide aperture short telephoto lens for portraits, blurred backgrounds or indoor sports

  • the classical portrait lens has a focal length in the range 85-120mm and has a wide aperture to give a shallow depth of field (DOF) and allow the subject to stand out from the blurred background
  • such a lens will be far more useful for most enthusiasts than a slow 3-4x 80-300mm kit lens with widest apertures around f/5.6, lower optical quality, slower AF and poorer bokeh.
  • it should have:
    • a nice quality to the background blurring (bokeh)
    • sharpness across the frame at widest aperture - mostly we do not want our subjects in the centre of the image
    • relatively compact so it is not intrusive upon the subject
    • relatively compact and light so we will bring it with us
    • fast AF, preferably with precise AF selectable on one or other eye of the subject (this is generally a camera functionality - such as Olympus Micro Four Thirds system)
  • my personal preference for focal length is at the long end as I find it suits my style better for compressing ugly, busy backgrounds into more aesthetic, lovely blurred ones, hence I used Canon EF 135mm f/2.0L lens, the manual focus Rokinon 85mm f/1.4 aspherical manual focus lens, and now the much lighter and smaller, Olympus m.ZD 75mm f/1.8 lens which has 150mm eq. focal length
  • full frame users often use 85mm f/1.4 lenses, or 70-200mm f/2.8 zoom lenses although these zooms are big, heavy, expensive, intrusive and prone to failure
  • Canon pro users sometimes use the 85mm f/1.2 lens but this has slow AF and is not an easy lens to use well
  • Canon and Nikon cropped sensor dSLR users often resort to a relatively cheap 50mm f/1.8 lens

night urban street walking wide angle lens

  • this requires the lens to be small so it can be hidden from would-be thugs, and be able to image night street scenes without a tripod
  • a great option for this is a wide angle lens with wide aperture combined with image stabiliser

macrophotography lens

  • many lenses allow close up shots, but to get really close, you need a dedicated lenses for macrophotography
  • longer focal lengths in the 120-200mm range generally allow for a longer working distance which means you don't have to get too close to the subject that it will fly away
  • if you are not shooting on a tripod, then a light, compact lens which will not fatigue your muscles and cause you to shake, can really help - a good example is the Olympus m.ZD 60mm f/2.8 macro lens which can also be used with ring or twin flashes and has an equivalent focal length of 120mm, fast AF, and handy focus limit switches while being weatherproof and very sharp for macro work at 1:1.
photo/lenses.txt · Last modified: 2013/11/07 12:03 by gary1